In terms of global mercury emissions, Indonesia is among the highest. According to UNEP data , Indonesia ranks third after India and China. Most emissions come from small, community-managed gold mines, often illegal. Another report stated that miners use more than three thousand tons of mercury per year throughout Indonesia.
Mercury, hydrargyrum [Hg], or common people know it as mercury, is used extensively in artisanal gold mining to separate gold ore from other metals or minerals. Usually by gold miners, mercury is mixed into a solution of sand or dust they produce.
Mercury binds to gold and forms amalgams or soft alloys of metals. Miners then collect this amalgam and then heat it until the mercury evaporates and the gold is left behind.
However, mercury is known to be a highly toxic, carcinogenic, and harmful metal to the environment. This silvery mercury is the only metal that is liquid at room temperature [25 degrees Celsius], will freeze at -39 degrees Celsius and has a boiling point of 356.7 degrees Celsius.
During the amalgamation process, some of the mercury will dissolve into the water and pollute rivers and oceans. Mercury binds to proteins so that it easily enters marine biota and becomes fatal when consumed by humans.
In people’s mining practices, evaporation of mercury is often done without safe procedures. As a result, many mining workers are exposed to mercury vapor.
Mercury exposure can cause poisoning, cancer, permanent disability, and even death. A well-known mercury-related event is the Minamata tragedy. At that time, about 50 thousand people were exposed to mercury from 1932 to 1968. More than 2,000 of these cases were proven to be related to this waste according to WHO.
In Indonesia cases of mercury contamination have also been found in areas where there are small-scale gold mining. A report stated that mercury content was found in the urine and hair of mining workers in West Nusa Tenggara. On Buru Island, Maluku, mercury content was found in sewage pond sediments. The same thing also happened in Lombok.
Research in a number of areas where there are mining sites also found that the content of methyl mercury in papaya, cocoa and rice was above the WHO threshold.
Fiber a lam
Indonesia will eliminate 100 percent of the use of mercury in the Small Scale Gold Mining [ASGM] sector by 2025. Actually, gold mining can be done without mercury. One of them is by utilizing palm fiber, as introduced by the Tambuhak Sinta Foundation.
Ijuk comes from the palm tree, which can grow in almost all parts of Indonesia. Traditionally. Palm fiber is used by the community for brooms, as well as roofs. The fibers are black, with a fine to coarse texture.
As a substitute for mercury, this organic fiber is used to catch gold grains dissolved in water. This method is claimed to be able to capture twice as much gold concentrate with even the finest grains. This method is also called the Manado method, because it was first practiced by miners in Manado.
The trick, previously cut palm fiber about 40 to 50 cm. Choose the middle part of the palm fiber because it is usually neat. The tip is removed, the palm fiber stick is also removed. Next, the fibers are arranged in stages similar to installing tiles and placed on the path that will be passed by water, which contains gold ore.
This water is a solution of rock containing gold ore that has previously been crushed in a crushing machine, called a spindle. Generally, miners would put mercury directly into these spindles. You can imagine what the consequences will be if mercury-contaminated water enters the waters.
Between the fibers installed wood. When installing, the wood is slightly pressed. The point, apart from holding the fibers in place, also serves to inhibit the flow of water from above which contains mud mixed with gold. Based on practice in the field, from 10 sacks of rock you can get 1 sack of concentrate and no gold is wasted.
The time needed is more or less the same when compared to using mercury. The palm fiber functions as a filter, so that the gold is retained in it, while most of the others are under the fibers. The water can then be disposed of directly into nature because it does not contain any hazardous materials.
After the solution in the logs is used up, the fibers are lifted and cleaned into a large container filled with water while being shaken so that the fibers come back clean. Palm fiber does not need to be thrown away because it can still be used again. The concentrate that remains in the path of the solution is then collected. Next, it is panned using a tool that resembles a plate but is large. Use it to separate the mud from the gold grains.
The gold grains obtained are heated and mixed with borax. Even in this process, workers do not need to worry about the effects of mercury poisoning because they do not use this liquid metal at all. The result is pure gold that is obtained in the right way, not polluting the environment.
In the market, mercury is sold for around Rp. 1 million per kilogram. Miners usually spend up to 3 kilograms of mercury, for one spindle process. By utilizing palm fiber , apart from being safe and friendly to the environment, miners can also save costs in obtaining gold. The results obtained can be even more because palm fiber is able to catch the softest gold grains which are often called gold dust.